Threading and testing machine



July 31, 1945.

J. E. HECKETHORN 2,380,841 THREADING AND TESTING MACHINE Filed April 17, 1944 2 Sheets-Sheet l INVENTOR. Jam 6 YfiMm/Y y 1945. J. E. HECKETHQRN 2;3s0,si1

THREADING AND TESTING MACHINE Filed April 17, 1944 2 Sheets-Sheet 2 IN V EN TOR.

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" Patented July 31 l UNITED STATES PATENT orncs Application April 17, :Qo. 531,515

7 Claims.

This invention relates to a threading device to be used either for tapping drill holes or for gautins and checking tapped holes. The principal object of the invention is to provide a simple, compact, rapid, unitary machine of the bench t p for tann ns work held against the machine byhand; which can be preset to tap all holes to an accurate uniform depth; and which will automatically reverse at thecompletion of .the tapping opeil'zation to rapidly unscrew the tap from the wor Another object of the invention is to provide a machine of this character which can be used to gauge or test tapped holes in articles, to deter-,

mine whether the thread therein depth and length.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efllciency. These will become more apparent from the following description.

In the following detailed description of the invention reference is had to the accompanying drawings which form a part hereof. Like numerals refer to like parts in all views and throughout the description.

In the drawings? Fig. l is a side view of the improved tapping is of the desired and thread gauging machine;

Fig. 2 is a top view thereof looking in the di-,

rection of the arrow 2, Fig. 1;

Fig. 3 is an enlarged longitudinal section through the spindle of the improved machine,

taken on the line 3-3, Fig. 2;

Fig. 4 is an end view of the tapping extremity of the machine; and

of the drawings or lathe and to present a spindle for receiving a chuck for holding the tap. These devices contain gears and friction clutches for driving the tap in a right-hand direction, as long as they are forced against the work, and in a left-hand direction when withdrawn from the work. The direction of rotation is controlled by shifting the spindle toward or away from the attachment.

This invention makes use of oneof these standard tapping attachments known to the trade as Procunier StyleE, illustrate'd at it supported from the bed plate on suitable brackets M. The

drive shank of the tapping attachment is indicated at I B. This shank was, of course, originally designed to be held in the chuck or spindle of a drill press or lathe, but in this machine a driven sprocket It is mounted thereon. The sprocket i3 is driven through to the medium of a suitable transmission chain H from an electric motor I8 which is supported on a side bracket Id 2mm the bed plate ii. The spindle of the tapping attachment, indicated at 20, which in the usual instal- I lation carries the tapping chuck, is provided with a shifting sleeve it by means of which it may be shifted back and forth between the "reverse and Fig. 5 is a cross section of the spindle, taken on the line 5-5, Fig. 3.

The improved machine is designed to be placed upon a work bench, such as indicated at Ill, or any other suitable support which will place the operating extremity thereof at a convenient hand height.

The mechanism is mounted: upon an inclined bed plate ll designed to rest upon the bench ID at its forward extremity and supported upon suitable legs If at its inner extremity. The legs I2 support the machine at an inclined angle on the bench to place the operating extremity at a convenient angle for the operator.

There are many tapping attachments available on the market designed to be placed in drill presses, lathes and the like. These tapping attachments are constructed to present a drive shanktobereceivedinthechuckofa'drillpress forward positions. I

A splined hub 22 is mounted in and projects a from the forward extremity of the shifting sleeve ii. The splined hub 22 is axially slidable in a hollow splined cup 23 which informed, or secured on, an axially fixed shaft 217. The shaft 21! is journalled in bearings 24 supported from a pedestal 26 onthe bed plate H. The shaft 21 is prevented from moving endwise by the cup 23 and a suitable set collar". When the shifting sleeve 2| is pulled from the tanning device i8, the direction of rotation of the shaft 21 will be reversed. The shifting of the sleeve simply moves the splined hub 22 inwardly and outwardly in the cup 23 so that the hub and the cup are always tied to rotate in unison. The outer extremity of the shaft 21 is provided with steel receiving socket in which any desired tool such as a thread gauge 28 or a tap may be secured lay-means of a suitable set screw 29 or in any other desired manner.

The shifting of the spindle so, which in the usual tapping device is accomplished by pulling or pushing upon the tap, is accomplished in this device by means of an A-shaped shifting yoke '10. The yoke is pivotally mounted on a yoke 5 shifting blocks 38 which are grooved on their inner faces for receiving the side edges of a thrust 2 ,sso,

bearing 34 which is rotatably mounted-on the shiftln sleeve II. I

It can be readily seen that as the yoke II is rocked back and forth it will shift the spindle of the tapping device It back and forthmto change the direction of rotation thereof.

yoke is rocked forwardly by means of a spring which is part of the mechanism of the standard tapping attachment l8 and is rocked rearwardly by means of a'solenoid II having a projecting armature member-8i. The armature member is connected by means of connecting links 31, to a threaded rod ll which passes through a receiving tube It on the upper extremity of the yokelnember 30. A nut ll is threaded on the rod II and servesto compress a spring ll against the tube 39 so as to cushion the pulling action of the rod on the yoke and to make it unnecessary to have accurate adjustment of movement of the solenoid armature.

The solenoid fl is controlled from a microswitch 42 which is actuated from a feeler finger 43 extending into the path of the work. The micro-switch 42 and its actuating feeler finger -43 are supported from a gauge plate 44. The

gauge plate 44 is mounted on a guiding slide rod 4! which through a guide hole in the pedestal 25. The tool, such as the thread gauge ually. A hand switcha is also provided by means of which the circuit to the solenoid control. may be closed should it,be desired to operate in reverse for a considerable period, The

motor is controlled from a remote control switch mounted in a motor control box II also having -start and "stop" buttons l2. An automatic timing switch is provided and enclosed ins-housing II; which holds the circuit to the solenoid closed for a preset interval after it has been. closed by the feeler 48 and the micro-switch 42.

Operation Letusassumethatthemachineistobeused for gauging the depth of threads in articles.

The thread'gauge II is placed in the shaft collar 20. The gauge plate 44 is adjusted by means of the nuts 41 sothat when the articleis thread ed on to thegauge to the desired depth the feeler.

43 will be contacted by the article to actuate the micro-switch; The motor ll is started by the start." button" on the motor box it. The operator now presses the article onto the rotating actuates the solenoid switch to deenerslze the solenoid. The timing switch-is so set as to allow the operator Just suilicient time to remove the articl from the gauge II. It then breaks the circuit to the solenoid to allow the spindle to shift to the position for right hand rotation for receiving the next article. If the threads in the article are too short, the article-will not reach the feeler arm 43 to actuate the solenoid and the articles will rotate in th operator's hand until the start" button I of the control switch ll I is actuated by hand to energize the solenoid to reverse rotation and release the faulty article for discarding. when the machine is used for tapping, the same procedure is followed except that. the gauge 28 is replaced by any desired tap. When the hole has been tapped to the desired depth the ieeler finger 43 will be contacted to reverse and unscrew the tap. Thus all holes tapped with the same setting of the gauge plate will be of uniform tap depth.

While a speciiicform of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Havingthus described the invention, what is claimed and desired secured by Letters Patent is:

l. The combination with a tapping device of the type having a drive shank and a driven spindle in which axial shifting of the spindle reverses the direction of rotation thereof, of a bed plate; means for supporting said device on said bedplate; means for rotating said shank; a driven shaft; means for supporting said driven shaft from said bed plate in axial alignment with the spindle of said device; a slidable, splined connection between one extremity of said shaft and said splindle; means for axially supporting a tool at the other extremity of said shaft; a thrust 'bearing mounted on said spindle; a pivotally mounted yoke operatively connected with said thrust bearing; a solenoid; an armature actuated by 'said solenoid; means connecting said armature with said yoke for rocking the latter to shift said spindle longitudinally; a gauge member adiustably positioned adjacent said tool; and contact means supported by said gauge member in the path of the work on said tool for .-actuating said solenoid at a predetermined point.

2. The combination with a tapping device of the type having a drive shank and a driven spindie in which axial shifting of the spindle revere.

the direction of rotation thereof, of a bed plate; means for supporting said device on said bed plate; means for rotating said shank; a drtven shaft; means for supporting said driven shaft .from said bed plate in axial alignment with the gauge II which is rotating right? If the thread is of, the proper depth the article will be drawn upon the gauge until the feeler finger 41 is contacted. This will instantly close' the microswitch, and through itthe circuit to the solenoid The solenoid causes the armature 30 and the yoke 30 to pull the spindle 2. of the tapping machine "outwardly, thus reversing the direction of rotation of the spindle II and the gauge 28. to quickly unscrew the gauge from the article. .The machine continues in operation in spindle of said device; a slidable, splined connectionbetween one extremity of said shaft and'sald spindle; means for xially supporting a tool at the other extremity of ,said vshaft; means for shifting said spindle longitudinally; a gauge member adjustably supported adjacent said tool; contact means carried by said gauge member to be contacted by the work on said tool: and means for actuating said shifting means in consequence of the contact of the work with said contact means.

. a. The combination with a tapping device of the type having a drive shank and a driven spindie-in which. axial shifting of the spindle reverses the direction of rotation thereof, of a' bed plate;

means for supporting said device on said bed the reverse direction until the timing switch plate; means for rotating said shank: a driven shaft; means for supportingsaid driven shaft from said bed plate in axial alignment with the spindle of said device; a slidable, splined connection between one extremity of said shaft and said spindle; means for axially supporting a tool at the other extremity of said shaft; a thrust bearing mounted on said spindle; a pivotally mounted yoke operatively connected with said thrust bearing; a solenoid; an armature actuated by said solenoid; means connecting said armature with said yoke for rocking the latter to shift said spindle longitudinally; a gauge member adjustably positioned adjacent said tool; a pivoted feeler arm supported by said gauge member with one of its extremities'in the path of the work on said tool; and an electrical contact closing device actuated by the other extremity of said feeler arm for actuating said solenoid.

4. The combination with a tapping device of the type having a drive shank and a driven spindle in which axial shifting of the spindle reverses the direction of rotation thereof, of a bed plate; means for supporting said device on said bed plate; means for rotating said shank; a driven shaft; means for supporting said driven shaft from said bed plate in axial alignment with the spindle of said device; a slidable, splined connection between one extremity of said shaft and said spindle; means for axially supporting a tool at the other extremity of said shaft; means for shifting said spindle longitudinally; a gauge member adjustably supported adjacent said tool; contact means carried by said gauge member to be contacted by the work on said tool; means for actuating said shifting means in consequence of the contact of the work with said contact means; and means for adjusting the position of said gauge member along said tool.

5. The combination of a tapping device of the type having a drive shank and a driven spindle in which axial shifting of the spindle reverses the direction of rotation thereof, of a bed plate; means for supporting said device on said bed plate; means for rotating said shank; a driven shaft; means for supporting said driven shaft from said bed plate in axial alignment with the spindle of said device; a splined hub on said spindle; a hollow splined cup on said driven shaft slidably receiving said hub; a bearing supporting said driven shaft from said bed plate, said bearing being arranged to prevent longitudinal movement of said shaft; tool supporting means on the free extremity of said shaft; and means for shifting said hub longitudinally in said cup to reverse said tapping device.

6. A device for gauging tapped holes comprising: a tapping attachment; a drive shank' projecting from said tapping attachment; a motor operatively connected to said drive shank for rotating the latter; a spindle projecting from said tapping attachment; a reversing mechanism in said tapping attachment, said reversing mechanism being operable inconsequence of longitudinal shifting of said spindle; a shaft supported in axial alignment with said spindle; means for preventing longitudinal movement of said shaft; means for transmitting rotative movement of said spindle to said shaft, at one extremity thereof; a tool receiving socket at the other extremity of said shaft; a thread gauge carried in said socket; electrical means for shifting said spindle axially to operate said reversing mechanism; a gauge plate surrounding said thread gauge; a feeler finger extending from said gauge plate towards said thread gauge; and a micro-switch operable from said feeler finger, said switch being in circuit with the electrical means for shifting the spindle.

7. A device for gauging tapped holes comprising: a tapping attachment; a drive shank projecting from said tapping attachment; a motor operatively connected to said drive shank for rotating the latter; a spindle projecting from said tapping attachment; a reversing mechanism in said tapping attachment, said reversing mechanism being operable in consequence of longitudinal shifting of said spindle; a shaft supported in axial alignment with said spindle; means for preventing 1ongitudina1 movement of said shaft; means for transmitting rotative movement of said spindle to said shaft, at one extremity thereof; a tool receiving socket at the other extremity of said shaft; a thread gauge carried in said socket; electrical means for shifting said spindle axially to operate said reversing mechanism; a gauge plate surrounding said thread gauge; a feeler finger extending from said gauge plate towards said thread gauge; a micro-switch operable from said feeler finger, said switch being in circuit-with the electrical means. for shifting the spindle; and means for adjusting the position of said gauge plate axially along said thread gauge.

JOHN E. HECKETI-IORN. 

